DEXA Scan Operation & Technique 3

Question 1

How should the technologist handle a patient who has received an oral contrast agent (barium) within the last 7 days before a DXA scan?

Accepted Answer

Reschedule the scan until contrast has cleared the GI tract

Answer

Barium contrast in the GI tract overlaps the lumbar spine on a DXA image and will falsely elevate BMD; the scan should be rescheduled.

Question 2

What is the recommended action if the femoral neck region of interest (ROI) is placed incorrectly during analysis?

Accepted Answer

Reposition the ROI manually and reanalyze the scan

Answer

Manual repositioning and reanalysis of the ROI is required to ensure accurate femoral neck BMD measurement without repeating radiation exposure.

Question 3

When performing a forearm DXA scan, the 33% radius (one-third site) is measured at what anatomical landmark?

Accepted Answer

One-third of the radius length from the wrist

Answer

The 33% radius site is located at one-third of the total radius length measured from the ulnar styloid (wrist) proximally along the radius.

Question 4

A technologist notices the DXA table laser alignment light does not activate during startup. What is the correct response?

Accepted Answer

Document and report the malfunction; do not scan until serviced

Answer

Malfunctioning positioning lasers should be reported and the unit should not be used for clinical scanning until the equipment is serviced and verified.

Question 5

Which scan acquisition parameter most directly affects the radiation dose delivered during a DXA scan?

Accepted Answer

Scan speed / mode (e.g., fast vs. high resolution)

Answer

Scan mode determines beam on-time and detector sampling rate, which directly affect the dose delivered; higher-resolution (slower) modes deliver more dose than fast-array modes.

(DEXA) DEXA Bone Density Scan Certification Practice Test

(DEXA) DEXA Bone Density Scan Certification Practice Test

DEXA Scan Operation & Technique 3